mudhog
THEGAME
how do you tell if your np208 chain is bad or needs replacing?
CK5
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how do you tell if your np208 chain is bad or needs replacing?
- Thread starter mudhog
- Start date
Thats a good question. I tend to stay away from chain drives except for my bicycle, which why I swapped my Borg-Warner 13-56 for a New Process 205.
So I may not be the best one to ask. But, the one time I was in a truck with a bad chain, it started jumping grooves, slots, teeth, whatever the heck you call where a roller chain hooks in.
When we got on it hard in 4wd, the truck would jerk and you would hear a loud popping noise and then it would start pulling again.
The chain was stretched just enough to jump and catch again.
There may be another way to tell by putting it in 4wd with the transmission in neutral and twisting the front and rear shafts in opposite directions to check on the play, but I'm not sure.
And, even if you did that, I'm not sure what the specs should be......
So I may not be the best one to ask. But, the one time I was in a truck with a bad chain, it started jumping grooves, slots, teeth, whatever the heck you call where a roller chain hooks in.
When we got on it hard in 4wd, the truck would jerk and you would hear a loud popping noise and then it would start pulling again.
The chain was stretched just enough to jump and catch again.
There may be another way to tell by putting it in 4wd with the transmission in neutral and twisting the front and rear shafts in opposite directions to check on the play, but I'm not sure.
And, even if you did that, I'm not sure what the specs should be......
You can tell a chain has gone bad when it gets its ear pierced, starts listening to heavy metal, having out with the wrong people...
IIRC, there's a spec for deflection, like for V-belts. The chain is bad when it's stretched too much, which you'd measure in the deflection.
Then of course you'd need the spec which is the piece I don't have
-- A
IIRC, there's a spec for deflection, like for V-belts. The chain is bad when it's stretched too much, which you'd measure in the deflection.
Then of course you'd need the spec which is the piece I don't have
-- A
Just like with FWD transaxle chains, there is a test you do to measure how much you can deflect it. You lay a straight edge across the sprockets and push on the chain. It's intended as part of the rebuild process, so it's based on having the case torn apart. It seems like you could do a qualitative test through the drain plug - maybe comparing it to a known good chain or something.
TheBeast_88K5
Banned
Pull that ****er out, and test deflection....
I'll get you the spec, hold on.
Edit:
The manual doesn't say.
Just pull it out and look at it.
I'm sure it'll be obvious.
I'll get you the spec, hold on.
Edit:
The manual doesn't say.
Just pull it out and look at it.
I'm sure it'll be obvious.
Or better yet, open the case, very carefully measure the deflection, down to the nearest .001 inch, then take it out and throw it away and replace it.
I mean, you already have the case open...................
mudhog
THEGAME
i was just wondering if it made any noise or anything. my new burb when going up hill or if i do more then gently accelerate it sounds like the fan is hitting the shroud. but it is not hitting and it dont do it when powerbreaking only when actually driving. it dose have an aluminum converter cover that i have heard have clearance issues so im going to pull that and see if that fixes it. i was just wondering if it was like the chain slapping or jumping teeth.
Well, the chain is only under load when in 4wd I think, so it won't be slipping. How many miles?
Those chain were good for probably 90K minimum unless abused or run low on oil.
There are lots of things that will sound like the fan hitting the shroud. The most common is the fan hitting something. Like the shroud, the radiator, a piece of stick or grass sticking through the rad.
I know you don't think so, but stop the engine and grab the fan and shake it and try to make it move in and out.
If it has a fan clutch, it can be going bad and letting it wobble. Or a cracked blade.
Get a good strong light, and examine everywhere that fan could possibly reach for a faint mark.
A bad motor mount would let it hit something under load that you would never think it could reach sitting still.
Also, assuming its an automatic, open the hood, crank it up and aim it in a safe direction.
Let someone with good ears stand off to the side, tell them under no circumstances get in front even to just walk to the other side to hear better.
Put the car in drive with you foot on the brake. Rev up slightly to see if it will make the noise. Tell them to listen and also watch the engine to see if it moves a lot.
Odds are they will at least be able to isolate it to a certain part of the truck.
Those chain were good for probably 90K minimum unless abused or run low on oil.
There are lots of things that will sound like the fan hitting the shroud. The most common is the fan hitting something. Like the shroud, the radiator, a piece of stick or grass sticking through the rad.
I know you don't think so, but stop the engine and grab the fan and shake it and try to make it move in and out.
If it has a fan clutch, it can be going bad and letting it wobble. Or a cracked blade.
Get a good strong light, and examine everywhere that fan could possibly reach for a faint mark.
A bad motor mount would let it hit something under load that you would never think it could reach sitting still.
Also, assuming its an automatic, open the hood, crank it up and aim it in a safe direction.
Let someone with good ears stand off to the side, tell them under no circumstances get in front even to just walk to the other side to hear better.
Put the car in drive with you foot on the brake. Rev up slightly to see if it will make the noise. Tell them to listen and also watch the engine to see if it moves a lot.
Odds are they will at least be able to isolate it to a certain part of the truck.
mudhog
THEGAME
ended up being the aluminum flyweel cover the converter bolts wear rubbing against the cover
Kjunky5
1/2 ton status
I had the same thing happen to me. It never sounded like it was coming from the transmission.
Sounds like a self correcting problem......Steel bolt heads vs aluminum.......
k20
3/4 ton status
Had the same problem when I put in a new flexplate. Took a grinder to the cover, thinned it out just a tick, and all is well.
